Firing mechanism of breech-loading guns.



A. T. DAWSON & G. T. BUCKHAM. FIRING MECHANISM 0F BREACH LOADING GUNS.

APPLICATION FILED IUNE2I|19I7 Patented Apr. 1.1919.

A. T. DAWSON & 61T. ucKHAM. FIRING MECHANISM 0F BREACH LOADiNG GUNS.

APPLICATION FIVLED JUNE 2l. 1917.

.Illl

Patented Apr. 1*, 1919.

A. T. DAWSON & 64T. BUCKHAM.

FIRING MECHANISM 0F BHEACH LOADING GUNS.

APPLICATION FILED JUNEZI. |917.

Patented Apr. 1, 1919.

4 SHEETS-SHEET 3.

A. T. DAWSON & G. T; BUCKHAM.

FIRING MECHANISM 0F BHEACH LOADING GUNS.

APPLICATION FILED 1UNE21. 1911.

Patented Apr. 1,1919.

4 SHEETS-SHEET 4.

UNiTED sTATEs PATENT oEEioE.

, ARTHUR TREVOB DAWSON AND GEORGE THOMAS BUCKHAM, 0F WESTMINSTEE,

LONDON, ENGLAND, ASSIGNOBS TO VICKERS LIMITED, F WESTMINSTEB,

LONDON, ENGLAND.

FIRING MECHA-N ISM HAM, both'subjects of the King of-Grreat l Britain,residing at-Vickers House, Broadv rel in single fire way, Westminster,in the county of London,

England, have invented certain new and useful Improvements in orRelating to the Firing Mechanism of Breech-Loading Guns, of which thefollowing is a specification.

' This invention relates to firing mechanism in which there isinterposed between the trigger or firing handle and the sear of thestriker or firing needle, a spring controlled member which, whenreleased bythe trigger, serves to transmit to the striker scar thenecessary'movement for disengaging it from the striker.

According to the invention we provide in an automatic gun means wherebythe aforesaid spring controlled member is 'automatically re-cockedduring the recoil ofthe baroperation, the said means preferablycomprising a cam carried by the operating crank of the breech mechanismor by any other suitable part contiguous to and Vmovin with the crank.The said spring contro led member may be in the form of a plunger withwhich engages a sear which is herein referred to as the secondary searto distinguish it from the striker scar. This secondary sear is adaptedto be displaced to release the spring controlled plunger by a sprincontrolled slip pawl or tripping piece w ich isy suitably connected tothe trigger or firing handle.

Means may be provided by the adjustment` of which the said slip pawl ortripping piece 'can at will be .caused-to perform its tripping functionin relation to the second- @ary sear (thereby firing single shots) orcan be prevented from performing this function in which'event the firingmechanism is set for the automatic operation of the gun. The said meansmay also be adjusted to a safe position in which condition thesecondarysear is prevented from being disengaged from the spring plungerandthe gun cannot then be fired.

It may happen that during the firingwof the gun the lock does not quitereach lts forward orl firing position, the actuatingv 'handle on thecrank shaft in consequence Specification of Letters Patent.

Fig. 1.

or BnEEcH-LOADINGGUNS.

being out of contact with its limit stop.

When this occurs it is customary to strike the actuat1ng handle smartlyto brin it against its limit stop and move the loc to its forwardposition; it has been found that- .means may comprise a safety sear forenratend Apr'. '1, 1 919.

Application illed June 21, 1917. VSerial-N9. 176,110. I f Y gaging witha member moving with the v spring controlled plunger, this safet Searbeing disengaged from thesaid mem er as the crank shaft completes itsmovement to bring the lock to its firing position.'

In order thatthe said mvention may be clearly understood and readilycarried into 'effect we will describe the same more fully with reference.to the accompanying drawings, in which Figure 1 isa side elevationvshowing more or less diagrammatically a constructional form of theinvention embodied in an automatic gun of the Maxim type, one side ofthe breech mechanism casing of the gun having been removed'to illustratethe invention moreclearly.

Fig. 2 is a plan of Fig.`1 with parts thereof in section on the lines 1,1 and 2, 2 of Fig. 3 is a side elevation,fviewed` in the direction ofthe arrow in Fig. 2, of the change fire device.

- Fig. 4 is a side elevation of Fig. 3.

Fig. 5 and 6 are views similar to Figs. 1

and Q-but with the muzzle of the gunA directed toward theleft---illustratii1g'v a constructional form of the means for preenlngthe gun from being prematurely re Fig. 7 is a sectiontaken approximatelyon lthfet line 3, 3 of Fig. 5 and viewed' from the Fig. is a sectiontaken approximately on theline 4, 4 of Fig. 5 and viewed from the`rlght.

A is the mechanismcasing of the automatic gun; A is the operating crankof the breech mechanism and A2 is the Crank shaft.V As represents theaforesaid cam moving with lthe crank A. 'B is the striker sear.v C

represents the spring controlled plunger and D represents the secondarysear appertaining to this plunger. E represents the spring controlledslip pawl or tripping piece for disengaging the said secondary sear fromthe plunger C. E2 (Figs. 5 to 7) represents the aforesaid safety scarfor preventing premature firing of the gun.

In the example .shown the spring plunger C is connected by a pin c to alongitudinally displaceable rod C whoseforward end is pivoted to an armC2* rigid with an arm C2 lying in Contact with the striker scar B. Therear end of this rod is connected to one arm o of a bell crank leverpivoted to the mechanism casing A, the other arm c2 being adapted to beoperated upon by the aforesaid cam A3 on the crank A of the breechmechanism. The secondary seai- D is of bell crank formation; itshorizontal arm has a nose-piece engaging with a recess or shoulder ofthe spring plunger C and its vertical arm is arrangede contiguous to theaforesaid spring controlled tripping piece E; the latter is pivoted tothe rear end of a sliding rod E suitably connected to the trigger orfiring handle which is not shown. When the trigger is arranged on theelevating or training handwheel or lever, the connecting vmeans comprisea bell crank lever e and a sliding pin e disposed co-axially withrespect to the trunnions ex.

The plunger C, the secondary scar D and the tripping piece E arearranged within a casing F upon the outside of which is' pivoted achange over lever F provided Within the casing with a curved arm fpivoted at 7"c tothe casing F and provided with a stop f. This stop isadapted to occupy three different positions by moving the arm f aboutits pivot; in the first or safety position Which is that shown in Fig. 1the stop cooperates with the vertical arm of the secondary scar D toprevent it from becoming disengaged from the langer C; in the second orautomatic fire position, which is indicated by the numeral 1 in Fig. 1,the stop f is situated above the upper surface of a recess lin thetripping y iece E when the latter is displaced toward t ie left to lirethe gun and this tripping piece is thereby prevented from performing itsslip function; in the third or single fire position which is indicatedby the numeral 2 in Fig. 1, the stop f is situated contiguous to anupward projection on the tripping piece so that when the latter isdisplaced to fire the gun it is moved by the stop into the positionshown by chain linesin Fig. 1 and is therebys1ipped from the secondarySear D.

When' the change over lever F and the stop f are in the single fireposition, the plunger is 1'e-cocked by the aforesaid cam As on theoperating crank A. When the said lever and stop are in the automaticlire position, the secondary Sear D is retained out of engagement withthe plunger C as long as pressure is exerted upon 'the trigger or firinghandle; in this condition of affairs the striker sear B is releasedautomatically as the barrel approaches for reaches its forward positionafter recoil, by the cooperation of part of the barrel extension withthe striker sear.

The initial manual cooking of the plunger C prior to automatic or singlefire operation is effected by the usual hand lever (not shown) on theouter part of the crank shaft A2.

- When this hand lever is actuated the aforesaid cam A3 on the crank Adepresses the bell crank lever c', c2 which is connected to thelongitudinally displaceable rod C', and ompresses and recocks the springplung The safety sea-r E2 (see Figs. 5 to 7) is pivoted at e2 to a fixedbracket E3 between which and the safety scar a spring e (Fig. 5) isinterposed; this spring tends to hold the safety sear in engagement withan extension c* of the arm c so that a shoulder on the safety sear E2(see Fig. 5) prevents the arm c and therefore the spring plunger'C frommoving to liberate the striker sear B. The safety sear E2 has an arm E2XWhich lies in the path'of a. projection A4 moving with the crank shaftA2. In the example shown this rojection is carried byl the aforesaid cam8 and is sol arranged that as the crank shaft' completes its movement tobring the lock to its firing position, the projection will come againstthe arm E2x and disengage the safety sear E2 from the extension 0' ofthe arm a.

. What we claim and desire to secure by Letters Patent of the UnitedStates is l. An automatic gun having'iring mechanism comprising a springcontrolled member which, when released, transmits movement to thestriker sear for releasing the striker, and provided with means wherebythe said member is automatically re-cocked during recoil of the barrelin single fire operation.

2. In an automatic un, the combination with the operating orari of thebreech mechanism and firing mechanism comprising a spring controlledmember which, when released, transmits movement to the striker sear forreleasing the striker, of means movingvangularly with said crank forautomatically re-cocking said member during recoil of the barrel .insingle fire operation.

l3. In an automatic gun the combination with the operating cran of thebreech mechanism and firing mechanism comprising a spring controlledmember which, when released, transmits movement to the striker sear forreleasi the striker, of a cam moving with the said operating crank in'such I manner that when the said crank is displaced during handoperation and during recoil of the barrel in single fire -operation itcocks .the said spring controlled member.

4. In an automatic gun, the combination of a spring controlled memberwhich when released transmits movement to the striker sear for releasingthe striker, a scar engaging with the, said member, a slip pawl ortripping piece for displacing the latter sear to release the springcontrolled member and means for at will causing the pawl or trippingpiece to perform or preventing it from performing its tripping function,substantially as described.

5. An automatic gun provided with firing mechanism comprising a spring.controlled member which when released transmits to the striker sear thenecessary movement for disengaging it from the striker, means forautomatically re-coc-king the said member during the recoil of thebarrel in single Y fire operation and means for preventing the saidmember from disengaging the striker 'sean until the lock approaches itsring position. v

6. An automatic gun provided with firing mechanism comprislng a springcontrolled member which when released transmits to the striker Sear thenecessary movement for disengaging it from the striker, means forautomatically re-cocking the said member during the recoil of the barrelin single fire operation, a safety sear adapted to prevent firingmovement of the said member and a projection moving with the crank shaftof the breech mechanism for displacing the safety scar to liberate thespring controlled member fas therlock approaches its firing position.

In testimony whereof We have hereunto affixed our signatures. c

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUCKHAM.

Witnesses:

JNO. R. CAsWELL, -GERTRUDE WHYTE.

